# CI Port Convention

## Reserved Range: 10000-10099

CI jobs never use production ports. Each service gets a fixed offset (1-99) within the 10000-10099 range.

**Formula:** `CI_PORT = 10000 + CI_PORT_OFFSET`

## Port Assignments

| Offset | CI Port | Service |
|--------|---------|---------|
| 1 | 10001 | NewsArchiverV2 |
| 2 | 10002 | paste-bin |
| 3-99 | 10003-10099 | Reserved for future services |

## Usage

**CI workflow:**
```yaml
docker run -d --name myapp-e2e \
  --network test-network \
  -e CI=true \
  -e CI_PORT_OFFSET=1 \
  myapp:test \
  python main.py --serve --port 5000
# App auto-shifts to port 10001
```

**App code (any service):**
```python
if os.environ.get("CI") == "true" and os.environ.get("SKIP_PORT_SHIFT") != "1":
    offset = int(os.environ.get("CI_PORT_OFFSET", "1"))
    args.port = 10000 + offset
    print(f"[ci-port-shift] Port shifted from {original} to {args.port}")
```

**Production:** Never sets `CI=true` or `CI_PORT_OFFSET`. Ports stay unchanged.

## Rules

1. CI jobs always set `CI=true` and the service's `CI_PORT_OFFSET`
2. Port discovery via log parsing: `docker logs | grep "\[ci-port-shift\]"`
3. Container-to-container traffic uses Docker networks, never host port publish
4. Production containers never have `CI=true`